Organisers will inspect the Mountain Course throughout this afternoon to see if conditions recover enough to allow this evening's Manx Grand Prix practice session to go ahead.
At least two inches of rain over the hills and over an inch at lower levels fell this morning, leaving large areas of standing water.
The weather is improving but Clerk of the Course Phil Taubman is worried about water running onto the roads from saturated land:-
Hockey: Cup finals confirmed
Men and Ladies Premier League top two to meet in last round
Rugby: Playoff hopefuls Douglas narrowly beaten at home
Vagabonds Ladies score big against Bury
Football: Three teams into FA Cup Semi-Finals
Onchan and Rushen to battle for place in final four
FC Isle of Man thrashed by ruthless Atherton
Ravens fall to joint-heaviest home defeat of season
FC Isle of Man to host in-form Atherton LR
Visitors currently on eight-match winning streak
